Diabetes mellitus, more commonly known as diabetes, is a disease characterized by hyperglycemia due to defective insulin secretion, insulin action, or both. Type 1 diabetes (previously known as insulin dependent diabetes mellitus (IDDM)) is an auto-immune disease that affects the islets of Langerhans, destroying the body's ability to produce insulin. Type I diabetes represents 10% of all diabetes cases and affects as many as 1 million people in the United States. Type 2 diabetes (previously known as non-insulin dependent diabetes mellitus (NIDDM)) is a metabolic disorder resulting from the body's inability to produce enough insulin or properly use the insulin produced. Roughly 90% of all diabetic individuals in the United States suffer from Type 2 diabetes. Type 1 and Type 2 diabetes are metabolic disorders characterized by hyperglycemia due to defective insulin secretion, insulin action, or both.
The prevalence of diabetes is increasing at an alarming rate. Between 1976 and 1994, diabetes among adults in the United States increased from 8.9% to 12.3% of the population. There are currently approximately 16 million people (6% of the population) in the United States who suffer from diabetes and roughly 800,000 people will be diagnosed with diabetes this year. (Harris et al. (1998) Diabetes Care 21:518-5241; Nathan (2002) N Engl J Med 347:1342-1349.) Diabetes can be associated—prior to, during, or after onset—with a wide range of conditions and complications affecting various organs throughout the body; for example, various microvascular diseases and other disorders, including, e.g., retinopathy, nephropathy, neuropathy, etc., leading to blindness, kidney failure, etc. Diabetes can severely compromise quality of life and can even be fatal. Therefore, there is a need in the art for effective means of treating and preventing the development and progression of diabetes and associated complications.
Several risk factors are associated with diabetes in general, and with the development of Type 2 diabetes in particular, such as a family history of diabetes, certain ethnic or racial groups, a history of gestational diabetes, obesity, in particular, high levels of visceral or abdominal fat, a sedentary lifestyle, age, high blood pressure, schizophrenia, etc., as well as altered glucose metabolism, including impaired glucose tolerance (IGT) or prediabetes. Therefore, there is a need in the art for effective means of treating and preventing the development and progression of risk factors associated with diabetes.
Conditions such as diabetes are associated with a loss in control of glucose regulation. Diabetic and hyperglycemic conditions can lead to development of, can develop in response to, or can otherwise be associated with various conditions and disorders including atherosclerosis, vascular disorders, e.g., stroke, etc., obesity, cardiac disease, e.g., congestive heart failure (CHF), myocardial infarction (MI), and downstream effects, etc., or with risk factors associated with these conditions and disorders. There is thus a need in the art for treating or preventing or for minimizing the risks of development of these conditions in association with diabetes or hyperglycemia. The present methods answer this need by providing a pharmacological approach that effectively permits administration of a single compound that targets a family of associated processes and achieves coordinated effects, in contrast to current approaches, in which different conditions and different aspects of different conditions can involve the application of multiple therapeutic approaches in order to achieve the desired therapeutic effects.
Current treatments for diabetes seek to control glucose levels in the blood (e.g., to achieve glycemic control), attempting to reproduce natural physiological glucose homeostasis. While lifestyle changes, e.g., controlled diet and increased exercise, can be recommended, this approach is limited in its effectiveness. Such lifestyle modifications might not prevent or counter the development of contributing physiological factors, and might delay, but not prevent, the progression of the disease. Additionally, lack of patient compliance can limit the effectiveness of this approach.
A common therapeutic approach involves treatment with insulin, e.g., through a course of injections that need to be administered in a carefully scheduled fashion, often requiring daily or even multiple daily injections. Treatments requiring injections of insulin carry with them associated risks of hypoglycemia and hyperinsulinemia. Further, the success of such treatments is often compromised by lack of patient compliance, i.,e., failure to follow the recommended treatment schedule. Additional insulin-based therapies, e.g., administration of insulin secretagogues (compounds that stimulate insulin release from the pancreas), similarly carry the risk of inducing hypoglycemia, etc. These therapies, and available treatments, e.g., PPAR-gamma agonist therapy, etc., are associated with other effects, for example, weight gain, a risk factor for diabetes in and of itself. Therefore, there is a need for methods and compounds for effectively treating or preventing diabetes, hyperglycemia, and associated risk factors for diabetes, such as weight gain and obesity, that offer improved ease of administration and that are not associated with development of or risk for development of other factors associated with diabetes, e.g., weight gain, etc. There is a need for a therapeutic approach to diabetes and related conditions that more closely mimics the body's own physiological mechanisms for achieving glucose homeostasis. There is a need for courses of treatment that have improved ease of administration, increasing patient comfort as well as the likelihood of patient compliance. Additionally, there is a need for treatments for diabetes or associated conditions, which treatments are not associated with effects that exacerbate or worsen the condition being treated.
Glucose metabolism, e.g., the synthesis, processing, and utilization of glucose, etc., is essential to maintaining proper glucose balance and homeostasis. A disruption in glucose metabolism or glucose regulation can lead to a disruption in glucose homeostasis, resulting in disproportionately high levels (i.e., hyperglycemia) or low levels (i.e., hypoglycemia) of blood glucose. Hyperglycemia and hypoglycemia affect quality of life and, in chronic or severe forms, produce neurological and vascular damage. There is thus a need for effective methods for regulating glucose metabolism and homeostasis (e.g., achieving glycemic control), and for methods for treating or preventing conditions and disorders associated with altered or impaired glucose metabolism and homeostasis, such as, e.g., diabetes, hyperglycemia, etc.
The present invention meets these needs by providing methods for treating or preventing diabetes, hyperglycemia, and associated disorders and risk factors. The present methods offer improvements over existing therapies by offering a coordinated therapeutic approach and improved routes of administration, and eliminating undesirable side effects associated with some treatments, e.g., weight gain, etc. Methods for regulating glucose metabolism and achieving glycemic control are also provided.